Morphometry and Physiology Core. The purposes of Core C are to evaluate the morphometric changes that occur during graft arteriosclerosis (GA) that culminate in constrictive remodeling and to assess the vasomotor function during the progression of GA in vitro. The combination of histological assessment and morphometric evaluation in conjunction with vessel physiology will allow us to dissect when vasomotor function contributes to GA remodeling. Core C will interface with Projects 1, 2 and 3 to assess the degree of remodeling and function in vessels undergoing GA in vitro and vessels modified in organ culture.